Polymerizable mixtures comprising a bivalent metal salt of an acrylate- or methacrylate-phthalate ester of an alkylene glycol

ABSTRACT

A POLYMERIZABLE SUBSTANCE IS PREPARED BY FIRST MAKING A BIVALENT METAL SALT OF A COMPOUND HAVING THE STRUCTURAL FORMULA   HOOC-C6H4-COO-R2-OOC-C(-R1)=CH2   WHEREIN R1 IS HYDROGEN OR METHYL AND R2 IS AN ALKYLENE GROUP WHICH MAY OR MAY NOT BE HALOGENATED, AND THEN MIXING SAID SALT WITH ANOTHER MONOMER CAPABLE OF COPOLYMERIZATION WITH IT. THE POLYMERIZABLE SUBSTANCE SO OBTAINED CAN BE USED IN PAINTS OR AS A MOLDING MATERIAL OR ADHESIVE.

States Patent US. Cl. 252-1883 11 Claims ABSTRACT OF THE DISCLOSURE Apolymerizable substance is prepared by first making a bivalent metalsalt of a compound having the structural formula l CHF-C-COORz-OOC COOHwherein R is hydrogen or methyl and R is an alkylene group which may ormay not be halogenated, and then mixing said salt with another monomercapable of copolymerization with it. The polymerizable substance soobtained can be used in paints or as a molding material or adhesive.

The present invention relates to a process for the preparation of apolymerizable substance having a metallic ionic bond. More particularly,the present invention relates to a process for the preparation of apolymerizable substance characterized by reacting a compound representedby the structural formula:

I CHz=COOORzOOC COOH wherein R represents hydrogen or methyl group and Rdenotes an alkylene group such as ethylene group, propylene group, or ahalogenated alkylene group such as chloropropylene, with an oxide orhydroxide of a bivalent metal in an inert solvent, such as benzene ortoluene, and mixing the metallic salt which is obtained by removing thesolvent after the reaction, with a monomer having the ability tocopolymerize with said metallic salt.

The term metallic ionic bond as used hereafter means the bond that isthe result of the ionic attraction between the metallic ion and theionized carboxylic acid group.

It is known that organic polymers which are bridged by metallic ionicbonds have various superior properties. Namely, the polymers haveheat-resisting property, shock resistance, tenacity and other superiorproperties. In order to obtain such, there have been proposed twoprocesses. One of the two processes is a process in which, for instance,first a linear polymer having a functional group capable of forming anionic bond, such as a carboxylic acid group at a side chain is prepared,then the metallic ionic bond is introduced. The other process is suchthat polymerizable monomer having the metallic ionic bond is firstprepared, and then said monomer is copolymerized with the otherpolymerizable monomer.

In general, the former process has been more widely employed. However,there are problems in introducing the metal. Namely, in order tointroduce the metal uniformly in the polymer, it is necessary to have ahighly efiicient 3,689,427 Patented Sept. 5, 1972 mixing operation andin order to eliminate the reaction byproduct having low molecularweight, produced by the neutralization reaction generally highevaporation temperatures are employed. Also, there is a limit to thequantity of the metal to be introduced. The latter process is regardedas an advantageous process since there is no problem as encountered inthe former process due to the fact that the metallic ionic bond isalready present before polymerization.

As a result of the various examinations of the process for thepreparation of polymer substances having metallic ionic bonds from theforegoing standpoint, the inventors have incented the present process.Namely, the inventors have found that a raw material composition forobtaining a polymer having superior properties can be prepared byreacting the compound which is generally represented by the generalstructural formula with an oxide or hydroxide, of a bivalent metal, andmixing the resulting salt, after removal of water and solvent, with amonomer capable of copolymerization therewith.

The compound represented by the structural formula can be easilysynthesized from a basic raw material which is produced at a low cost onan industrial scale. In case R is hydrogen, it is an acrylic acidderivative and if R, is methyl group, it is a methacrylic acidderivative. Now the gist of the process of synthesis of the structuralformula will be described with reference to the case in which R is theethylene group. The end product can be prepared by effecting a halfesterification reaction of hydroxyethyl acrylate or hydroxyethylmethacrylate with phthalic anhydride or phthalic acid, ortho, meta orpara. In this case, it is advantageous to use phthalic anhydride as theprocess is not accompanied with dehydration and yet the haflesterification can be easily carried out. Also, in this case, there isno restriction with respect to quantitative relation between thehydroxyl compound and acid anhydride, but for the acid anhydride, theend product can be easily prepared by using a slightly excessivequantity of hydroxyl compound, namely, 1.2 to 1.5 mol of hydroxylcompound for 1 mol of acid anhydride since such use of the compoundaccelerates the reaction. As described in the foregoing passage, thereis a case in which excessive unreacted hydroxyl compound exists in thereaction product depending upon the quantitative relation of thereaction system to be applied, but it may be removed after the reactionis carried out, or it may be used in the succeeding neutralizationreaction as it is instead of removing it because it has a polymerizabledouble bond in itself. In the structural formula, R represents a glycolresidual group, namely, an alkylene group or a halo-carrying alkylenegroup, and the length of chain is not particularly limited, but it ispreferable to have a relatively shorter length of chain,

R can be such a group as No more than one halogen may be present in theR group.

Now, the compound which is represented by the structural formula thusobtained is dissolved in an inert solvent such as benzene and tolueneand the like, and is agitated at a low temperature, or room temperatureor high temperature, and a fixed quantity of oxide or hydroxide ofbivalent metal is added in suitable quantity while the agitation iscarried out to effect the neutralization reaction. The metal of theoxide or hydroxide of bivalent metal which is employed in the reaction,for instance, can be magnesium, calcium, zinc, cadmium, barium, lead andso on. Also, the quantitative relation of the oxide or hydroxide ofbivalent metal and carboxylic acid group is not particularly limited,but 0.5 to 1.0 equivalent of oxide or hydroxide for one equivalent ofcarboxylic acid group is preferable. As described above, it is highlysignificant that an industrially low cost and advantageous metal oxideor hydroxide is employed as the raw material for the preparation ofmetallic salt. As the solvent, there is no particu* lar requirement aslong as it is an inert solvent, but it is preferable that such materialas benzene, toluene, acetone or methylethylketone, which is relativelyeasy to remove after the reaction is completed, be used. In most cases,the neutralization reaction progresses at a considerable speed at a lowtemperature or room temperature, but in order to raise the speed of thereaction further a high temperature (preferably 60-80 C.) may beadvantageous. The water which is produced by the reaction can be removedwith the solvent at the time of removal of the solvent after thereaction is completed. Also, in case the solvent is benzene, the watercan be removed out of the system by reflux after the reaction or duringthe reaction.

The metallic salt of the acid of the structural formula is a novelcompound. It may be obtained in varying viscosities up to a solidsubstance depending on the kind of the metal or the quantitativerelation of carboxylic acid group and metallic oxide and hydroxide. Themetallic salt may be polymerized singly, but it is far more advantageousto mix it with another polymerizable monomer not only from thestandpoint of the operation but also from the physical property of thepolymer to be obtained.

The copolymerizable monomers that can be employed in the process are,for instance, styrene, methylmethacrylate, ethylmethacrylate,hydroxyethylmethacrylate, propylmethacrylate, butyl methacrylate,methylacrylate, ethylacrylate, divinylbenzene, ethylene glycoldimethacrylate, vinyl acetate and mixtures thereof.

The object of the present invention is achieved by mixing acopolymerizable monomer with said metallic salt.

The polymerization reaction proceeds at room temperature or a hightemperature by adding polymerization catalyst or high temperatures alonewill suifice. The mixing ratio of the metallic salt to copolymerizablemonomer is about 1:1 to about 1:20 by weight but if the weightquantities of both substances are substantially equal, a polymersubstance having superior properties can be obtained. Namely, thepolymer obtained is of the heat resistant type and has high tenacity andis superior in shock resistance and adhesive property. It is apparentthat the polymer prepared is one in which bridging is carried out bymetallic ionic bonds.

On the other hand, as a copolymerizable monomer, a monomer having twodouble bonds in one molecule such as divinyl benzene or a monomer havingmore than two double bonds may be employed. In this case, the polymer tobe prepared is considered as forming a net polymer by both covalentbonds and metallic ionic bonds.

The polymerizable substance of the present invention has many uses suchas molding material, paint, adhesives and others.

The present invention is now described concretely with a referenceexample and applied examples.

REFERENCE EXAMPLE: (PREPARATION OF EMP) titativelyethyleneglycolmethacrylate phthalate (hereinafter referred to as EMP) isprepared. The reason for employing 2-hydroxyethylmethacrylate in morethan a quantity theoretically calculated is that it minimizes the amountof unreacted phthalic anhydride. The end product is a light yellowtransparent liquid and its acid value is 187.0 (theoretical value is184.6).

APPLIED EXAMPLE 1: (MG SALT OF EMP) 122 g. of EMP and 2 00 g. of benzeneare placed in a four-necked flask provided with a water contentseparating means, thermometer, and agitation means, and while vigorouslyagitating, 8.06 g. of magnesium oxide powder is added. Immediatelythereafter, the benzene is refluxed, and the agitation is continuedwhile heat is applied. Water amounting to 69% of theoretical quantity isseparated after the elapse of 5 hours, and the benzene reflux liquidbecomes transparent. After the unreacted magnesium oxide is filtered outand the benzene is removed, a high viscosity liquid having magnesiumsalt of EMP as its major component is prepared.

APPLIED EXAMPLE 2: (CD SALT OF EMP) 30.5 g. of EMP, 60 g. of benzene areplaced in a flask having the same means as in the case of AppliedExample 1, and while the mixture is sufliciently agitated at roomtemperature, 6.42 g. of cadmium oxide powder is added. The reaction isaccompanied with slight heat generation. After the heat generation isover, and when the benzene is refluxed, water of of theoretical quantityis separated after the elapse of 2.5 hours, and the benzene refluxliquid, becomes transparent. Thereafter, the benzene is removed; thecadmium salt of EMP in the form of a light yellow transparent glass isprepared almost quantitatively.

APPLIED EXAMPLE 3: (BA SALT OF EMP) 30.5 g. of EMP and 60 g. of benzeneare placed in a flask having the same means as in the case of AppliedExample 1, and while the mixture is sufliciently agitated at a roomtemperature, 7.67 g. of barium oxide powder is added gradually to themixture. The reaction is accompanied with considerable heat generation.After the heat generation is cover, the benzene is refluxed, and waterof theoretical quantity is separated. Then, when the benzene is removed,the barium salt of EMP in the form of a light brown color glass isprepared almost quantitatively.

APPLIED EXAMPLE 4: (PB SALT OF EMP) 30.5 g. of EMP and 60 g. of benzeneare placed in a flask having the same means as in the case of theApplied Example 1, and while the mixture is sufliciently agitated, 11.2g. of powder of lead monoxide is added. The reaction is accompanied withconsiderable heat generation, and it reaches a temperature of 34 C.after the elapse of several minutes. After the heat generation is over,the benzene is refluxed, and then water of 89% of theoretical quantityis separated and the system becomes transparent. Thereafter, when thebenzene is removed, the lead salt of EMP in the form of a light yellowhigh viscosity liquid is prepared almost quantitatively.

APPLIED EXAMPLE 5 (CD SALT OF EAP) 28.8 g. ofethyleneglycolacrylatephthalate (hereinafter referred to as EAP), whichis prepared by the same operation as in the case of the ReferenceExample from Z-hydroxylethylacrylate and phthalic anhydride, and 60 g.of benzene are placed in a flask having the same means as in the case ofthe Applied Example 1, and while the mixture is sutficiently agitated,7.32 g. of powder of cadmium hydroxide is added to the mixture. Thebenzene is refluxed, and after the product water is separated, and thebenzene is removed, the cadmium salt of EAP in the form of a lightyellow glass is prepared almost quantitatively.

APPLIED EXAMPLE 6: (BULK POLYMERIZATION OF A POLYMERIZABLE SUBSTANCEINCLUD- ING AN EMP OR EAP SALT) A metallic salt of EMP or EAP, preparedas in Examples 1 through 5 and methylmethacrylate, or a 1:1 by weightmixture of methylmethacrylate and styrene, are mixed at a ratio of 1:1by Weight, and to the mixture is added 0.4 Weight percent of a 60%dimethylphthalate solution of methylethyl ketoneperoxide and the mixtureis polymerized for several hours at a temperature of 80 C. As a result,a polymer having superior mechanical strength, heat resisting property,adhesive property and chemical reagent-resisting property is obtained.

More specifically, the mixture of EMP magnesium salt andmethylmethacrylate by weight ratio 1:1 which is polymerized has heatdistortion temperature 139 C. (ASTM D 648 fiber stress 18.56 kg./cm.Rockwell hardness 110 (ASTM D 785 M scale), compression strength 1600kg./ cm? (ASTM D 695), tensile strength 895 kg./cm. (ASTM D 638). Thepolymer has a strong adhesive property when prepared by bulkpolymerization between metal plates such as iron and aluminum. Thepolymer shows thermal stability which is superior to that of aconventional thermosetting resin such as polyester as shown by thermalanalysis.

While the weight ratio of the two monomers in Applied Example 6 is 1:1,said ratio is not critical and can generally vary from 1:1 to metal saltmonomer to other monomer to 1:20.

Other copolymerizable monomers such as styrene, ethylmethacrylate,hydroxyethylmethacrylate, propylmethacrylate, butyl methacrylate,methylacrylate, ethylacrylate, divinylbenzene, ethylene glycoldimethacrylate, vinyl acetate and mixtures thereof yield similar resultsin the process of this example.

What is claimed is:

1. A polymerizable mixture consisting essentially of a bivalent metalsalt of a compound represented by the formula 5 COOH wherein R ishydrogen or methyl and R is an alkylene group or a monohaloalkylenegroup, and a polymerizable ethylenically unsaturated compound, theweight ratio of said metal salt to said polymerizable compound beingfrom about 1:1 to about 1:20.

2. The polymerizable mixture of claim 1 wherein said polymerizableethylenically unsaturated compound is selected from the group consistingof styrene, methylmethacrylate, ethylmethacrylate,hydroxyethyhnethacrylate, propylmethacrylate, butylmethacrylate,methylacrylate, ethylacrylate, vinyl acetate, divinylbenzene, ethyleneglycol dimethacrylate and mixtures thereof.

3. The polymerizable mixture of claim 1 wherein the weight ratio ofpolymerizable metal salt to said polymerizable ethylenically unsaturatedcompound is about 1:1.

4. The polymerizable mixture of claim 1 wherein R is selected from thegroup consisting of CHZB r CH I 5. The polymerizable mixture of claim 1wherein the bivalent metal is selected from the group consisting ofmagnesium, calcium, cadmium, zinc, barium and lead.

6. The polymerizable mixture of claim 1 wherein the metal salt is themagnesium salt of ethyleneglycolmethacrylatephthalate and saidpolymerizable ethylenically unsaturated compound is methylmethacrylate.

7. The polymerizable mixture of claim 1 wherein said polymerizableethylenically unsaturated compound is an equal weight mixture of styreneand methylmethacrylate.

8. The polymerizable mixture of claim 7 wherein the weight ratio ofpolymerizable metal salt to said polymerizable ethylenically unsaturatedcompound is about 1:1.

9. The polymerizable mixture of claim 7 wherein the bivalent metal isselected from the group consisting of magnesium, calcium, cadmium, zinc,barium and lead.

10. A polymerizable mixture consisting essentially of a bivalent metalsalt of a compound represented by the formula CHF-OOORzOOO wherein R ishydrogen or methyl, R is selected from the group consisting of andpolymerizable ethylenically unsaturated compound selected from the groupconsisting of styrene, methylmethacrylate, ethylmethacrylate,hydroxyethylmethacrylate, propylmethyacrylate, butylmethacrylate,methylacrylate, ethylacrylate, vinyl acetate, divinylbenzene, ethyleneglycol dimethacrylate and mixtures thereof, the ratio by weight of saidmetal salt to other copolymerizable monomer being from about 1.1 toabout 1:20.

11. A process for the preparation of a polymerizable mixturecharacterized by reacting a compound of the formula COOH wherein R ishydrogen or methyl and R is an alkylene group or a monohaloalkylenegroup with an oxide or hydroxide of a bivalent metal in an inert solventand mixing the metal salt so obtained, after removal of the solvent,with a polymerizable ethylenically unsaturated compound, the weightratio of polymerizable metal salt to said polymerizable ethylenicallyunsaturated compound being from about 1:1 to about 1:20.

References Cited UNITED STATES PATENTS 3,367,992 2/1968 Bearden 260-475N HERBERT B. GUYNN, Primary Examiner I. GLUCK, Assistant Examiner US.Cl. X.R.

252182; 260-785 R, 429.9, 435 R, 475 N, 515 P

